Either Vector is the most understanding boyfriend of all time, or it's his thing. I'm not sure which.
Ok, in all seriousness, this did happen to me when I played SWTOR. I brought Vector along because I wanted to know how he would react to Sha flirting with Phi-Ton (cutie) and then the marriage too. Vector LOVED that Sha was so accepting of the alien culture. He loved it so much, in fact, that I gained those necessary approval points to trigger Vector's proposal convo. It was quite awkward.
It should be noted that if you are married by the time you get to Voss, Vector won't be quite as happy. So I have been told.

Haha, I was married to Vector and still did all the marriage in Voss, and he was totally chill with it. I think it was all the "oooo I like diplomacy and alien cultural acceptance" that made Vector okay with it. I think he said something to that effect, complete with saying something to the effect of being the "main squeeze" made it okay to go all the way! :)

There are some really weird relationships in TOR. My Inquisitor some how accidentally slept with another Sith on Alderaan, and Andronikos acted like it was the greatest thing ever. I see those two competing for points like Hawke and Isabella.

@randomch: I'm afraid that I must admit that I escaped out of that convo and avoided it before any accepting could be done. Sha might be genuinely fond of Vector, but she's also quite xenophobic and the idea of genuinely marrying a non-chiss (as in, not for the sake of a mission) is just a no-go. And I can't handle Vector's sad face :(

@randomch: I knoooow D: I feel super bad about it, and it's not like it goes away. He just wants to have the Important Rock Giving Talk every time I log in and it's just... ahahaha... uh... so about the um... mission :I

Ouch. Sounds like you need to log in and then hand the computer to someone else to break up with him for you, while you sit with your back to the screen, humming loudly and sticking your fingers in your ears.